Searched hist:"875 f1d0769cdcfe1596ff0ca609b453359e42ec9" (Results 1 – 1 of 1) sorted by relevance
| /linux/include/linux/ |
| H A D | uio.h | diff 875f1d0769cdcfe1596ff0ca609b453359e42ec9 Wed Feb 27 21:05:25 CET 2019 Jens Axboe <axboe@kernel.dk> iov_iter: add ITER_BVEC_FLAG_NO_REF flag
For ITER_BVEC, if we're holding on to kernel pages, the caller
doesn't need to grab a reference to the bvec pages, and drop that
same reference on IO completion. This is essentially safe for any
ITER_BVEC, but some use cases end up reusing pages and uncondtionally
dropping a page reference on completion. And example of that is
sendfile(2), that ends up being a splice_in + splice_out on the
pipe pages.
Add a flag that tells us it's fine to not grab a page reference
to the bvec pages, since that caller knows not to drop a reference
when it's done with the pages.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|